The present invention relates to an image processing device, an endoscope apparatus, an image processing method, and the like.
The state of small concavities and convexities on the surface of tissue is normally observed when determining whether or not a lesion (e.g., an early lesion in the digestive tract) is benign or malignant, or determining the range of the lesion using an endoscope apparatus. A method has been normally used that enhances the contrast of concavities and convexities by spraying a dye so that the concavities and convexities can be easily found. However, since the dye spraying operation is cumbersome for the doctor, and increases the burden imposed on the patient, it is advantageous for the doctor and the patient if concavities and convexities can be detected by image processing.
For example, JP-A-2003-088498 discloses a method that detects concavities and convexities by comparing the brightness level of an attention pixel in a locally extracted area with the brightness level of its peripheral pixel, and coloring the attention area when the attention area is darker than the peripheral area. The method disclosed in JP-A-2003-088498 is based on the assumption that a distant object is captured darkly since the intensity of reflected light from the surface of tissue decreases.